1. Field of the Invention
The present invention related generally to the field of surgical procedures and, in particular, to the placement of sutures in tissue. More specifically, the present invention relates to a device and method to suture tissue of a patient that is particularly advantageous for less invasive surgical procedures performed within the heart and great vessels.
2. Background Art
Various types of surgical procedures are currently performed to investigate, diagnose, and treat diseases of the heart and the great vessels of the thorax. Such procedures include replacement of mitral, aortic, and other heart valves, repair of atrial and ventricular septal defects, treatment of aneurysms, and other procedures which interventional devices are introduced into the interior of the heart of a great vessel.
Of particular interest to the present invention are intracardiac and intraluminal procedures for surgical treatment of heart valves and great vessels. According to recent estimates, more than 79,000 patients are diagnosed with aortic and mitral valve disease in U.S. hospitals each year. More than 65,000 mitral valve and aortic valve replacement procedures are performed annually in the United States.
A heart valve may be replaced using various techniques. The valve leaflets of the native valve are excised, and a replacement valve is secured in the valve position, usually by suturing the replacement valve to the natural valve annulus. Various types of replacement valves are in current use, including mechanical and biological prostheses, as well as homografts and autografts.
When investigating, diagnosis, or treating diseases of the heart and the great vessels of the thorax, many current techniques require a gross thoracotomy, usually in the form of a median sternotomy, to gain access into the patient""s thoracic cavity. A saw or other cutting instrument is used to cut the sternum longitudinally, allowing two opposing halves of the anterior or ventral portion of the rib cage to be spread apart. A large opening into the thoracic cavity is thus created, through which the surgical team may directly visualize and operate upon the heart and other thoracic contents.
Cardiac surgery remained largely unchanged while other surgical specialties moved rapidly toward less invasive operations. In recent times, however, heart surgery has begun to turn in a minimally invasive direction. Less-invasive surgical procedures have recently been developed which avoid the need for gross thoracotomy, such as a median sternotomy. Patients can be placed on cardiopulmonary bypass machines using minimally invasive techniques, and instruments have been developed to access and operate on the contents of the thorax without having to open vastly the chest.
The minimally invasive techniques subject the patient to less trauma and less recovery time and development has been occurring at a feverish pace, fueled by the media and patient preference as well as commercial developments that have made minimally invasive heart surgery possible. These minimally invasive operations probably represent the infancy of a new era of cardiac surgery. In the future, many coronary bypass operations may be performed as ambulatory procedures with same day or next day discharge. Patients will return to full activity within a week. Cardiac valve procedures will remain inpatient procedures with hospital stays of approximately three days and return to normal activity will occur at two weeks.
At present, select coronary artery bypass procedures can be performed without the use of cardiopulmonary bypass or median sternotomy. Both mitral and aortic valve replacements can now be performed through limited incisions that avoid sternal splitting.
Regardless of the surgical technique employed, common to many cardiac surgical procedures is the need to place sutures in the heart or other tissue within the thoracic cavity. For example, in the case of heart valve replacement, the valve prosthesis is usually sutured to tissue on or around the patient""s native valve annulus.
A particular problem for minimally invasive techniques involves placing sutures in heart or other tissue that is accessed from outside of the patient""s chest through small access ports presents a variety of difficulties. For instance, maneuverability is often difficult due to the limited space between the ribs. Further, when accessing the contents of the thoracic cavity through an intercostal space, visibility is limited, thereby making it difficult to properly place the suture. Further, such procedures can become time-consuming, particularly when placing a single suture at a time. Placing sutures in an annulus of a heart valve for attachment of a replacement valve is especially challenging. The suture needle must be inserted through the valve annulus in a direction toward or away from the surgeon, creating difficulty in seeing and manipulating the needle as it passes through the annulus.
Frequently, a curved needle is used in order to drive the needle deeper into the annulus tissue so that the suture will not tear out of the tissue. However, such a curved needle must be driven in an arc about an axis parallel to the plane of the annulus, whereas in less-invasive procedures, the surgical approaches used to access the heart valves dictate that the needle holding instrument be oriented at an angle perpendicular to the plane of the annulus. The needle must therefore be driven in a curved path about an axis roughly perpendicular to the shaft of the instrument. With the angular motion of the instrument highly limited when positioned through a small intercostal access port, the ability to drive a curved needle in an accurate path through the valve annulus is greatly compromised.
What is needed, therefore, are devices and methods for improved suture placement when access to the tissue is limited, such as in less-invasive surgical procedures. In particular, the devices and methods should reduce the size of the incision needed to access the internal anastomotic site. The device should place uniformly precise suture bites within the interrupted suture line. The device should simplify the placement of sutures by simultaneously placing all sutures, necessary to affix a prosthesis, at once. The devices and methods should reduce the time required to place the suture.
The present invention addresses the needs in the art by providing a method and device for suturing tissue, in which the device includes a tube of a size to be inserted into a surgical site, such as into an artery of a patient. The tube includes a suction opening laterally circumscribing at least a portion of the tube to allow fluid communication between the tissue of the patient at the surgical site and the bore of the tube. Also within the tube is a carriage for detachably holding at least one needle, in which the carriage is slidably movable within the bore near the suction opening of the tube. When the tube is properly positioned, a vacuum source is placed in fluid communication with the bore of the tube so that the tissue is drawn into the suction opening of the tube. The carriage is then slid within the bore so that the needles detachably held thereby traverse the tissue, thus quickly and efficiently placing sutures in the tissue at the surgical site.
In an exemplary embodiment, the invention provides for the placement of sutures within the heart or great vessel that is accessed from outside the closed thoracic region. According to one exemplary method, the patient""s heart valve is accessed through a small port in the patient""s chest. The patient""s diseased or damaged heart valve is excised using endoscopic intrumentation. The heart valve annulus is then ready to accept interrupted sutures used to affix a heart valve prosthesis.
The present invention provides surgeons a means for quickly and precisely placing annular sutures through the smallest possible skin incision. Utilization of the present invention will minimize trauma to the patient, provide precise placement of sutures in the annular plane, and dramatically reduce cross clamp time. The present invention, accordingly, replaces the most time consuming and technically challenging portion of minimally invasive valve replacement surgery with a few simple motions or actions by the surgeon.